DFT+eDMFT study of lattice dynamics in FeSe

Effect of electron-electron interactions in the high-temperature superconductivity has been one of the challenging issues in condensed matter physics. We study the lattice dynamics of one of the iron-based high-temperature superconductors FeSe using ab-initio Density Functional Theory (DFT)+ embedded Dynamical Mean-Field Theory (eDMFT) functional approach. We found that the electron-electron interaction plays an important role in determining the phonon frequencies of different vibrational modes in this material. The phonon frequencies are in a very good agreement with the experimentally reported values in particular when compared to previously reported DFT results. The agreement extends also in the phonon band structure along with the phonon density of states.